Field of the Invention
This invention relates to a winding core for supporting thereon a roll of elongated windable material such as thread, cord, tape or the like, and more particularly to a core structure particularly suitable for winding a paper punch tape used with an electronic computer.
Elongated strips, cords and tapes of paper, cloth or synthetic resin are widely used in various fields for diversified purposes, for example, in the packaging and data processing industries. These strips and tapes are usually provided in the form of a roll but are easily loosened by rough or inadvertent handling, lowering their working efficiency to a considerable degree.
The paper punch tapes for electronic computers on the market generally have a length of 270 meters and a width of 1 inch and are tightly wound around a paper board core of a cylindrical shape. However, it is rare that such a paper board core of cylindrical shape is used when wholly or partially punched paper tape is wound. Usually, clips, rubber bands or other means are applied to the outer surface of the rewound punched tape which has been at least once unwound for punching, in order to prevent the punched tape from unravelling. But the innermost end of rerolled punched tape is usually left free. Cores for rerolling punched paper tape are not available on the market. The reason why such cores are not available on the market is that the winding reels exist in different diameters.
Even if a user were to make a suitable cylindrical core for rewinding, he would find it tedious to attach one end of the punched tape to the core. In addition, the pasted part of the punched tape would disturb in the reading of the last part of the tape by a computer. In handling rolled paper tapes which have been already punched, operators are usually required to pay special attention not to dislodge the rolls from their winding cores since, once a portion of the rolled tape is dislodged, the roll has to be completely disentangled and rewound. The rewinding operation is often time-consuming because the rolled tapes are twisted at every turn and the twisted tapes have to be straightened during the re-winding operation, the tapes being broken in some cases. The tendency of the wound tapes to unravel is increased as they are used with greater frequency. Spontaneous unravelling of the rolled tapes sometimes occurs even during storage.